Black Holes: Can Anything Reduce Their Size?

[elusiveshame]

I'm pretty sure I know the responses I'm going to get, as this question is pretty silly, but I'll ask anyway.

Is there anything - a process, or a material, that would reduce the size of a black hole and/or evaporate it away quickly, or is that just hocus pocus thinking?

 

[A.T.]

https://en.wikipedia.org/wiki/Hawking_radiation#Black_hole_evaporation

 

[elusiveshame]

https://en.wikipedia.org/wiki/Hawking_radiation#Black_hole_evaporation

Yeah, I know about Hawking Radiation, but that's a natural and slow process, right?

Is there any other way that could happen by a man-made approach that would accelerate the evaporation?

 

[A.T.]

Yeah, I know about Hawking Radiation, but that's a natural and slow process, right?

The duration depends on the size of the BH:
https://en.wikipedia.org/wiki/Micro_black_hole#Hawking_radiation

 

[PeroK]

Is there any other way that could happen by a man-made approach that would accelerate the evaporation?

I don't think that's a silly question at all! I suspect that the answer is no. But, the idea of some sort of stimulated evaporation is a lot more plausible than some of the really silly questions we get.

That said, currently black holes are governed theoretically by GR, with the QM effect of Hawking radiation being something of an anomaly. If and when we have a theory of quantum gravity, then the possibilities for how a black hole behaves may change.

 

[elusiveshame]

I don't think that's a silly question at all! I suspect that the answer is no. But, the idea of some sort of stimulated evaporation is a lot more plausible than some of the really silly questions we get.

That said, currently black holes are governed theoretically by GR, with the QM effect of Hawking radiation being something of an anomaly. If and when we have a theory of quantum gravity, then the possibilities for how a black hole behaves may change.

Thanks for the answer. That's what I figured the likely answer would be: no

Would there be any benefit to speeding up that process (if it were possible and plausible to do so) aside from maybe preventing a head on collision with one, if one were detected to be heading towards us? When a BH evaporates, there's no point in which we'd be able to "see inside" of it because it'd still be shrouded by the event horizon, yeah? Or would it become "visible" once the mass reaches a certain level?

 

[PeroK]

Would there be any benefit to speeding up that process (if it were possible and plausible to do so) aside from maybe preventing a head on collision with one, if one were detected to be heading towards us? When a BH evaporates, there's no point in which we'd be able to "see inside" of it because it'd still be shrouded by the event horizon, yeah? Or would it become "visible" once the mass reaches a certain level?

A black hole is not a mass-eating monster! The gravity of the black hole is the same as the collapsed star from which it formed - as long as you remain beyond the original surface radius of the star. I.e. if the Sun became a black hole, this would not directly affect the Earth's orbit. It's only if you get within the original suface radius that the gravity is greater - and once you reach the event horizon, then there is no going back.

In that sense, a black hole would be no more dangerous than a rogue star of the same mass. And, the danger of a rogue star is extremely low risk.

 

[elusiveshame]

A black hole is not a mass-eating monster! The gravity of the black hole is the same as the collapsed star from which it formed - as long as you remain beyond the original surface radius of the star. I.e. if the Sun became a black hole, this would not directly affect the Earth's orbit. It's only if you get within the original suface radius that the gravity is greater - and once you reach the event horizon, then there is no going back.

In that sense, a black hole would be no more dangerous than a rogue star of the same mass. And, the danger of a rogue star is extremely low risk.

D'oh. I feel like I knew this, too. Thanks for the reminder :)